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Tailoring photonic metamaterial resonances for thermal radiation

Peter Bermel*, Michael Ghebrebrhan, Michael Harradon, Yi Xiang Yeng, Ivan Celanovic, John D Joannopoulos and Marin Soljacic

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Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA

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Citation and License

Nanoscale Research Letters 2011, 6:549  doi:10.1186/1556-276X-6-549

Published: 6 October 2011

Abstract

Selective solar absorbers generally have limited effectiveness in unconcentrated sunlight, because of reradiation losses over a broad range of wavelengths and angles. However, metamaterials offer the potential to limit radiation exchange to a proscribed range of angles and wavelengths, which has the potential to dramatically boost performance. After globally optimizing one particular class of such designs, we find thermal transfer efficiencies of 78% at temperatures over 1,000°C, with overall system energy conversion efficiencies of 37%, exceeding the Shockley-Quiesser efficiency limit of 31% for photovoltaic conversion under unconcentrated sunlight. This represents a 250% increase in efficiency and 94% decrease in selective emitter area compared to a standard, angular-insensitive selective absorber.

PACS: 42.70.Qs; 81.05.Xj; 78.67.Pt; 42.79.Ek

Keywords:
metamaterials; photonic crystals; solar absorbers